1. Doing the wrong thing, then later realizing that you could have gone about it in a much better fashion. Short for "douche bag angle".

2. Trying to be shifty or sleazy in a situation and blowing it only to realize later that you completely looked like an ass in the process. Regret weighs heavy.

Say a girl best described as "plain jane" that you see everyday gets a MAD makeover and like an ass you try to lay some smoothness on her only to be shot down with the realization that you knew her all along. If only you hadn't taken the douchebangle you'd probably be cozy with her right now.

Example in a sentence:

"If only he didn't try some slippery douchebangle I probably would have went to the prom with him".